Simon Burge wrote;

>> I was more interested in the previous paragraph:
>>
>> * 64-bit extensions: many MIPS CPUs are 64-bit machines which are
>>   32-bit comp tible.  64-bit pointers are rarely useful outside big Unix
>>   sytems, but using 64-bit data can be worthwhile. SDE-MIPS generates
>>   64-bit instructions for ``long long'' data, while keeping a valuable
>>   degree of compatibility with the 32-bit calling convention. 

The portion sounds nice and practical (than adapting SGI N32/N64
throughoutly), but must be handled with great care.  It's uncertain
theirs can offer LP64 which is required for NetBSD/mips64.

Tohru Nishimura